Content Strand 2: Measurement - Item Specification (8-2005)

ME02 (Units and Systems) Explain how selection of a unit affects the precision of a measurement in a given situation; demonstrate understanding of the difference between square and cubic units (1.2.2, 1.2.3)

Item Format:

· Multiple-Choice and Short-Answer items may be used to test this learning target.

Stimulus, Stem, and Prompt Rules:

· Stimulus may include pictures, tables, charts, diagrams, figures, illustrations, and written descriptions.
· Items will not require students to convert from U.S. to metric or metric to U.S.
· The answer and distracters will be stated in terms of the same system of measurement.
· Conversion facts may be given in an item, e.g., 1 mile = 5,280 feet.

Mathematical Vocabulary and Terms:

· Terms that may be used: area, centimeter, cubic units, foot/feet, gram, inch, gram, kiloliter, kilometer, length, liter, meter, mile, milligram, milliliter, millimeter, ounce, pound, square unit, volume, width, yard
· Terms that may be used with definitions or examples:
· Terms that may not be used:
· Students are expected to know how to determine the following:

Perimeter of a polygon

Area of a rectangle Area of a triangle

Volume of a rectangular prism

Item Characteristics:

a) Items may ask students to identify how the selection of units affects precision.
b) Items may ask students to describe or explain how the selection and use of units affects precision.
c) Items may ask students to explain how measurement systems allow for different levels of precision.
d) Items may ask students to explain why there are different sized units in a measurement system.
e) Items may ask students to identify cubic units as measures of volume versus square units as a measure of area.
f) Items may ask students to explain why volume is measured in cubic units and area is measure in square units.
g) Items may ask students to explain how the size of a unit of length affects the size of square and/or cubic units.
h) Items may ask students to explain the relationship between square and cubic units within the same system.
i) Items may ask students to convert between units within a system to demonstrate understanding of precision in a given situation.

Note: Students are expected to determine and label units.